GPS measurements of near-field deformation along the southern Dead Sea Fault System

Abstract

[1] Analysis of short-term deformation along the southern part of Dead Sea Fault (DSF) provides a systematic view of kinematics this part of the continental transform. The southern DSF consists of two principal segments: the Wadi Araba and Jordan Valley faults. In addition to other regional continuous GPS data, this study uses new data from 25 survey sites and 4 continuous GPS stations in Jordan for improved near-field observations. Resulting velocities are reported with 1-s uncertainties ranging from 0.4-1.0 mm/yr. Application of elastic dislocation models yields estimates of slip rates for Wadi Araba and Jordan Valley faults are 4.9 ± 0.4 mm/yr and 4.7 ± 0.4 mm/yr, respectively. Modeling also suggests different depths of effective fault locking with 15 ± 5 km and 8 ± 5 km for the Wadi Araba and Jordan Valley faults, respectively. These slip rates are generally consistent with the upper end of the range of slip rates estimated from late Quaternary geology. Spatial variations in effective fault locking generally correspond with a heterogeneous mantle lithosphere. A similar observation can be observed along the southern San Andreas Fault, and this may reflect the influence of heterogeneity in the uppermost mantle on crustal faulting processes.

Variable behavior of the Dead Sea Fault along the southern Arava segment from GPS measurements

“…We thus propose that the velocity of the central part of the Wadi Arava fault is presently close to 4.7-4.8 mm/yr. This value is comparable to the values of 4.9 mm/yr and 5.0 mm/yr reported by Al-Tarazi et al (2011) andSadeh et al (2012) for the central part of the Wadi Arava fault. This is also consistent with the large-scale block model of Reilinger et al (2006) for the region (4.5 AE 0.3 mm/yr for the Wadi Arava fault).…”

“…Second, on the Arabian plate, a small but significant eastward movement is observed for all the sites, indicating a small east-west extension along the Arava valley. This is consistent with the extension of 0.6 mm/yr proposed by Reilinger et al (2006) and Al-Tarazi et al (2011) along the fault.…”

“…3a and b), the RMS is 0.38 mm/yr. These results are indistinguishable from the results proposed earlier by Le Bé on et al (2008), Al-Tarazi et al (2011) and Sadeh et al (2012) who obtain a velocity of 4.9 AE 0.7 mm/yr, 4.9 AE 0.4 mm/yr and 5.1 mm/ yr (4.7-5.4 mm/yr) respectively, and a locking depth of 11.5 AE 5.1 km, 15 AE 5 km and 15.5 km (12.1-23 km), respectively. The current study presents a reduction of the standard deviation of both the locking depth and slip rate compared to Le Bé on et al (2008).…”

“…The velocity is varying from a rate of $ 5 mm/yr along the southern and central segments to a rate of $ 2 mm/yr along the northern segment (north of 358N). An average locking depth of 11 AE 9 km is proposed along the southernmost segment (Al-Tarazi et al, 2011;Le Bé on et al, 2008;Sadeh et al, 2012) while this locking depth is very difficult to estimate along the northernmost segment (Alchalbi et al, 2010).…”

“…Recent studies have characterized the first order geodetic velocity field around the DSF (Alchalbi et al, 2010;Al-Tarazi et al, 2011;Gomez et al, 2007;Le Bé on et al, 2008;Reilinger et al, 2006;Sadeh et al, 2012;Wdowinski et al, 2004). The velocity is varying from a rate of $ 5 mm/yr along the southern and central segments to a rate of $ 2 mm/yr along the northern segment (north of 358N).…”